package org.apache.maven.lifecycle.internal;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.maven.artifact.ArtifactUtils;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.project.MavenProject;

/**
 * A list of project segments, ordered so that all ProjectSegments from first TaskSegment come
 * before any subsequent TaskSegments.
 * 
 * @since 3.0
 * @author Kristian Rosenvold
 *         <p/>
 *         NOTE: This class is not part of any public api and can be changed or deleted without
 *         prior notice.
 */
public class ProjectBuildList implements Iterable<ProjectSegment> {
  private final List<ProjectSegment> items;

  public ProjectBuildList(List<ProjectSegment> items) {
    this.items = Collections.unmodifiableList(items);
  }

  // TODO: Optimize; or maybe just rewrite the whole way aggregating mojos are being run.
  /**
   * Returns aProjectBuildList that contains only items for the specified taskSegment
   * 
   * @param taskSegment the requested tasksegment
   * @return a project build list for the supplied task segment
   */
  public ProjectBuildList getByTaskSegment(TaskSegment taskSegment) {
    List<ProjectSegment> currentSegment = new ArrayList<ProjectSegment>();
    for (ProjectSegment projectBuild : items) {
      if (taskSegment == projectBuild.getTaskSegment()) { // NOTE: There's no notion of taskSegment
                                                          // equality.
        currentSegment.add(projectBuild);
      }
    }
    return new ProjectBuildList(currentSegment);
  }

  public Map<MavenProject, ProjectSegment> selectSegment(TaskSegment taskSegment) {
    Map<MavenProject, ProjectSegment> result = new HashMap<MavenProject, ProjectSegment>();
    for (ProjectSegment projectBuild : items) {
      if (taskSegment == projectBuild.getTaskSegment()) { // NOTE: There's no notion of taskSegment
                                                          // equality.
        result.put(projectBuild.getProject(), projectBuild);
      }
    }
    return result;
  }

  /**
   * Finds the first ProjectSegment matching the supplied project
   * 
   * @param mavenProject the requested project
   * @return The projectSegment or null.
   */
  public ProjectSegment findByMavenProject(MavenProject mavenProject) {
    for (ProjectSegment projectBuild : items) {
      if (mavenProject.equals(projectBuild.getProject())) {
        return projectBuild;
      }
    }
    return null;
  }

  public Iterator<ProjectSegment> iterator() {
    return items.iterator();
  }

  public void closeAll() {
    for (ProjectSegment item : items) {
      MavenSession sessionForThisModule = item.getSession();
      sessionForThisModule.setCurrentProject(null);
    }
  }

  public int size() {
    return items.size();
  }

  ProjectSegment get(int index) {
    return items.get(index);
  }

  public Set<String> getReactorProjectKeys() {
    Set<String> projectKeys = new HashSet<String>(items.size() * 2);
    for (ProjectSegment projectBuild : items) {
      MavenProject project = projectBuild.getProject();
      String key = ArtifactUtils.key(project.getGroupId(), project.getArtifactId(), project.getVersion());
      projectKeys.add(key);
    }
    return projectKeys;
  }

  public boolean isEmpty() {
    return items.isEmpty();
  }
}
